I put an Akrapovic exhaust on my 2010 M1100 abs today, an have attached a video below, of what the bike sounds like in the four phases: stock, headers, baffles in and baffles out.
I left the baffles out at the end. The system sounds pretty good -- full, mellow, strong, not boomy or bappy. At 50 mph and above, in the windstream, it sounds fantastic. From 20 to 35 it's a little loud, but I don't think too loud. I may ride if for a week or two and then try a week or two with the baffles in. It was not as loud as my brother's old GT1000 with the full Termi system without baffles.
The installation was easy. Most of the fittings were perfect. The right hanger-to-band alignment wasn't perfect, but still fit easily once it was tightened down.
I ordered it from Revzilla, for about $1,040.
Looks and sound are subjective, of course, but I liked it a lot and would be very surprised if anyone installed it and didn't like it. It's not cheap, but it's less than the Termi's. I did not want the CF Termi's, and just couldn't bring myself to pay for the Titanium Termi's.
I was pleasantly surprised at how smoothly the engine ran after the installation. There were a few decel pops, but mainly when engine braking down a hill. Overall, I'd say it ran great. I'll put the video of the sound at different stages, as well as a picture. I was pretty happy with the look.
I'm happy with the package, and would buy Akrapovic again.
Akrapovic muffler on Monster 1100![](http://jettanderson.smugmug.com/Motorcycles/2010-Monster/P1010209/1032925594_q4jGR-XL.jpg)